CVE-2020-21674

Name: CVE-2020-21674
Creator: NVD / NIST
Published: 2020-10-15T15:15:11.28+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.06%

Last modified Jun 17, 2026

CVE-2020-21674 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Heap-based buffer overflow in archive_string_append_from_wcs() (archive_string.c) in libarchive-3.4.1dev allows remote attackers to cause a denial of service (out-of-bounds write in heap memory resulting into a crash) via a crafted archive file. NOTE: this only affects users who downloaded the development code from GitHub. EPSS estimates a 2.06% chance of exploitation in the next 30 days.

Description

Heap-based buffer overflow in archive_string_append_from_wcs() (archive_string.c) in libarchive-3.4.1dev allows remote attackers to cause a denial of service (out-of-bounds write in heap memory resulting into a crash) via a crafted archive file. NOTE: this only affects users who downloaded the development code from GitHub. Users of the product's official releases are unaffected.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

2.06%

78.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Libarchive	Libarchive	3.4.1

References

https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4Patch, Third Party Advisory
https://github.com/libarchive/libarchive/issues/1298Third Party Advisory
https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4Patch, Third Party Advisory
https://github.com/libarchive/libarchive/issues/1298Third Party Advisory

Timeline

Published: Oct 15, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-21674?

How severe is CVE-2020-21674?

CVE-2020-21674 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.06% probability of exploitation in the next 30 days.

How do I fix CVE-2020-21674?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-21674?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST